From c861fa9202d7e5c3e30079cded2366271c02075e Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Thu, 29 Mar 2018 13:48:24 -0700
Subject: [PATCH] Use 'map.get' instead of 'has' (#22998)

---
 src/compiler/checker.ts | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 7cfa500a326..89348b1b6c4 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2503,11 +2503,8 @@ namespace ts {
             }
 
             const id = "" + getSymbolId(symbol);
-            let visitedSymbolTables: SymbolTable[];
-            if (visitedSymbolTablesMap.has(id)) {
-                visitedSymbolTables = visitedSymbolTablesMap.get(id);
-            }
-            else {
+            let visitedSymbolTables = visitedSymbolTablesMap.get(id);
+            if (!visitedSymbolTables) {
                 visitedSymbolTablesMap.set(id, visitedSymbolTables = []);
             }
             return forEachSymbolTableInScope(enclosingDeclaration, getAccessibleSymbolChainFromSymbolTable);